EP1554086B1 - Power tool - Google Patents

Abstract

The electric tool has a universal motor (16) for driving the tool (17) provided with a motor shaft (34), a self-supporting stator (18), an armature (32) and a collector (36) provided with brushes. A support part (20,22) is attached to each end of the stator, the brushes and the brush holder attached to one of the support parts and the motor shaft supported by the latter.

Description

The invention relates to a power tool according to the preamble of claim 1.

Such a power tool is from the DE-C-940477 known. In the known power tool is a power tool with two shell half with longitudinally split housing. The motor is designed as a cantilevered flange motor, with its flange is bolted to the supporting housing shell. As a result, a simple structure and easy installation are guaranteed.

Such power tools have been known for many years.

Usually power tools are powered by universal motors. A universal motor usually has a housing, within which a stator is provided with Polfeldwicklungen, within which an armature is rotatably arranged. The armature is received on a motor shaft which is rotatably supported by bearings on the housing. Further, a universal motor has a fan provided at a first end of the armature and a collector with brushes provided at the other end of the armature.

Such universal motors have proven to power electric tools due to the low power-to-weight ratio and the universal applicability for DC and AC. As before, there is a demand for a weight reduction, an increase in performance or after a reduction in size while maintaining performance in power tools. Furthermore, as a result of rationalization efforts is constantly the demand for a simple and inexpensive construction and after a simple installation in the room. Furthermore, the highest possible reliability is also sought when used in continuous operation.

In power tools with a rod-shaped housing always results in a certain power class a certain shaft diameter, which is why a certain minimum diameter results for a rod housing due to the necessary collector and associated brushes. Now, if the power of such a power tool to be increased, then results in a larger diameter of the rod housing, which disadvantageous for the handling is because too large diameter can be covered only with difficulty by hand.

The invention has for its object to provide an improved power tool, which is designed particularly ergonomic and has the lowest possible power to weight ratio.

This object is achieved by a power tool according to claim 1.

The object of the invention is completely solved in this way.

In the power tool according to the invention, the collector is arranged between the fan and the winding package of the armature. With such an arrangement, a shorter design of the power tool can be realized. Also in this way a more favorable ergonomics is achieved. This is particularly advantageous if this embodiment is combined with the aforementioned self-supporting embodiment of the stator and the two supporting parts received thereon. If switches are to be received in the region of the first handle part, for example in an embodiment as an optical switch, a certain space for installation of the switch is necessary anyway. This can also be used to install the collector in this area. In that regard, collector, brushes and one or more switches can be accommodated in the area of the first support part, whereby the overall size can be reduced. Further, no coal dust is blown from the brushes by the engine. According to the invention, the first support part as a result of the anyway required for the brush space as air guide for designed a favorable air flow to the fan out. As a result, a nozzle effect can be achieved at the same time. This leads to better cooling and thus to improved performance.

According to an advantageous embodiment of the invention, a self-supporting construction is used, which leads to a weight reduction and thus to an improved performance weight. In this case, all other components of the power tool can be attached to the self-supporting stator by means of the two support parts. These include, for example, a housing of the power tool, one or more switches, and control electronics for controlling the electric motor.

Preferably, the brushes with brush holder and at least one switch are accommodated on a first of the support parts, while the control electronics and at least one switch are accommodated on a second of the support parts.

This results in a particularly space-saving and weight-saving construction.

In a further advantageous embodiment of the invention, the two support members are connected to a housing.

In this way, the supporting parts of the power tool can be attached to the support parts and the support parts can be equipped with a variety of functions, while the housing, which must be particularly adapted for the ergonomic handling of the power tool, can be attached to the support members. As a result, the supporting function of the support parts and the outer design of the housing decoupled from each other and facilitates the assembly.

According to a further embodiment of the invention, a tool head, in which the tool is used, attached to a first of the two support parts.

In contrast, the motor shaft is preferably in bearings on the tool head and mounted on a second support member.

If necessary, in this case, the tool head may include a transmission.

These features support a modular, particularly space-saving and ergonomic design of the power tool

According to a further embodiment of the invention, a switch is mounted at least on the first support member, which is actuated via an activation surface received on the housing.

In this case, an activation surface is preferably formed both on the first and on the second support part, so that a rod-shaped power tool can be held with one or two hands. The activation surface itself can either be formed directly on the relevant support parts or on the housing, which extends over the relevant support part away.

On the first support part, opposing brush holders are accommodated according to a further embodiment of the invention.

According to a development of this embodiment, the first support part has means for electrically connecting the brushes to the stator.

In this way, the structure is further simplified. For this purpose, a contacting can be provided, for example, directly on the supporting part which otherwise consists of insulating material and be guided to the stator via a plug-in connection. Optionally, a cable connection may be provided.

In an additional development of the invention, a gripping surface, which is tapered in the area between the two opposing brush holders, is provided on the first support part.

The housing may be formed approximately oval in this area.

By this embodiment, the disadvantage is avoided, which is due to the relatively large distance in the region of the two opposing brushes. Instead of making the gripping surface rotationally symmetric in this region, an approximately oval or elliptical shape of the gripping surface is chosen so that the larger cross section between the two brushes can be achieved with a smaller cross section in the intermediate region. Thus, even with a higher power of the power tool, a gripping surface is made possible with a relatively small gripping distance for the fingers.

The two support members are preferably made of an insulating material, in particular of plastic.

As a result, a favorable weight is achieved on the one hand, and on the other hand can be made of plastic complicated shaped parts in a casting process. In particular, when electrical switches are to be accommodated on the support parts, an insulating embodiment is particularly advantageous. As a result, the necessary contact safety for power tools that are operated with mains voltage can be achieved in a simpler manner.

In particular, when the power tool is equipped with optical switches, this touch security can be produced in a particularly simple manner.

According to a further embodiment of the invention, at least one activation surface for actuating a switching element of a switch is provided at least on one of the two support parts.

With such an embodiment, a particularly ergonomic mixer structure can be achieved, again in particular when optical switches are used as switches, which operates approximately by means of optical fibers, between which the signal transmission is influenced by a control element.

According to a further embodiment of the invention, a fan is held in the region between the first support member and the tool head in the region between the first support member and on the motor shaft.

In this way, the fan can advantageously be partially integrated in the first support part and partially in the tool head in order to achieve a particularly space-saving arrangement.

As already mentioned above, an embodiment with tern or sensors, in particular in the form of light-optical elements, is particularly preferred. In each case at least two light guides are provided, which are associated with a transmitter and a receiver, and a control element for influencing the transmitted light signals between the optical fibers.

Such optical switches or sensors can be accommodated in a particularly space-saving manner on almost any parts of the power tool, whereby the overall ergonomics can be significantly improved.

For such a design with light guides, it is preferable to use a support member for receiving the light guide, which has a shaped body, is provided in the recesses into which the light guides are inserted.

This has the advantage that the light guides are better protected against shocks, environmental influences and the like, and that the assembly is simplified because the light guide before can be integrated into the support element, so that only an already completed support member must be mounted.

In this case, the shaped body preferably has receptacles for transmitting or receiving elements assigned to the optical fibers or for switching elements for influencing radiation, which is transmitted by the optical fibers.

Furthermore, the shaped body can have accommodation for LEDs.

In this way, the light guides can be attached together with the associated transmitting or receiving elements and, together with the associated switching elements on the support elements, whereby a total of a simpler structure and easier installation is possible.

Furthermore, it is preferred that the shaped body interacts with the housing of the power tool for sealing the light guide received in the shaped body and / or transmitting or receiving elements or switching elements coupled thereto against contamination by dust or the like.

In this case, the molded body can form a completely sealed structural unit with the housing.

In this way, a greater reliability is achieved because dust and the like are shielded by the support member of the light guides. This is especially important for power tools where a high level of dust is expected, such as with grinders.

In an additional development of the invention, the molded body consists of a vibration-damping and / or acoustically damping material. Also, damping elements on the molding, e.g. be attached by gluing. These may be, for example, foam elements.

Also by these measures, the reliability is improved and also achieved a more favorable ergonomics.

It is understood that the features of the invention mentioned above and those yet to be explained can be used not only in the respectively specified combination but also in other combinations or alone, without leaving the scope of the invention.

Fig. 1

eine Aufsicht eines erfindungsgemäßen Elektrowerkzeuges in Form eines Winkelschleifers mit einem stabförmigen Gehäuse;

Fig. 2

eine vereinfachte Darstellung des Elektrowerkzeuges gemäß Fig. 1, bei dem die Schutzhaube weggelassen wurde, jedoch, der im stabförmigen Gehäuse aufgenommene Motor nebst Stator und zwei daran befestigten Stützteilen eingezeichnet ist;

Fig. 3

eine vergrößerte Seitenansicht des Elektrowerkzeuges gemäß Fig. 1, bei dem jedoch lediglich der Werkzeugkopf nebst Stator sowie erstem und zweitem Stützteil erkennbar ist;

Fig. 4

einen Längsschnitt durch das Elektrowerkzeug gemäß Fig. 3;

Fig. 5

einen Längsschnitt durch das Elektrowerkzeug gemäß Fig. 4, jedoch in vergrößerter Darstellung, in einer um 90°gegenüber der Schnittebene gemäß Fig. 4 versetzten Schnittebene;

Fig. 6

eine vergrößerte Darstellung des Elektrowerkzeuges gemäß Fig. 5 im Bereich zwischen Werkzeugkopf und Stator, wobei zusätzlich ein Tragelement mit darin aufgenommenen Lichtleitern zur Ausbildung von optischen Schaltern dargestellt ist;

Fig. 7

eine Gesamtansicht des Tragelementes gemäß Fig. 6;

Fig. 8

eine Ansicht des Lichtleiterbündels, das in das Tragelement gemäß Fig. 7 eingesetzt ist;

Fig. 9

eine Ansicht des Elektrowerkzeuges gemäß Fig. 2 schräg von oben, jedoch mit eingesetztem Tragelement nebst Lichtleitern;

Fig. 10

eine Seitenansicht des Elektrowerkzeuges gemäß Fig. 9 und

Fig. 11

einen Querschnitt durch das Elektrowerkzeug im Bereich der Bürsten.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings. Show it:

Fig. 1

a top view of a power tool according to the invention in the form of an angle grinder with a rod-shaped housing;

Fig. 2

a simplified representation of the power tool according to Fig. 1 in which the protective cover has been omitted, however, the motor accommodated in the rod-shaped housing is shown in addition to the stator and two supporting parts attached thereto;

Fig. 3

an enlarged side view of the power tool according to Fig. 1 in which, however, only the tool head in addition to stator and first and second support member is recognizable;

Fig. 4

a longitudinal section through the power tool according to Fig. 3 ;

Fig. 5

a longitudinal section through the power tool according to Fig. 4 However, in an enlarged view, in a 90 ° relative to the cutting plane according to Fig. 4 offset cutting plane;

Fig. 6

an enlarged view of the power tool according to Fig. 5 in the region between the tool head and the stator, wherein additionally a support element with light guides received therein is shown for forming optical switches;

Fig. 7

an overall view of the support element according to Fig. 6 ;

Fig. 8

a view of the optical fiber bundle, which in the support element according to Fig. 7 is used;

Fig. 9

a view of the power tool according to Fig. 2 obliquely from above, but with inserted support element together with light guides;

Fig. 10

a side view of the power tool according to Fig. 9 and

Fig. 11

a cross section through the power tool in the brushes.

In Fig. 1 a power tool according to the invention is shown in the plan view and designated overall by the numeral 10.

In the case shown, it is an angle grinder with rod-shaped housing, which is suitable for a one-handed operation or a two-handed operation. On the tool head 14 of the power tool 10, a protective cover 15 is provided in the usual way. The housing 12 has a taper in the region of the transition to the tool head 14, on which switches are provided on both sides, which can be actuated via elastic activation surfaces 27. The housing 12 is designed in this area with a gripping surface 24 which can be grasped with one hand from above or below, wherein both opposing activation surfaces of the switch can be taken.

In the remote from the rear portion of the housing 12, which tapers towards the end approximately conically, a second gripping surface 26 is formed, which in turn has on each side of an activation surface 28 for actuating a switch formed below.

The switches are preferably designed as optical switches, with light guides, between which the transmitted signals can be influenced via control elements, the light guides transmitting and receiving elements are assigned, as basically from the German patent application 101 41 161.8 and the parallel U.S. Patent Application 10 / 214,844 known, not pre-published and whose disclosure is fully incorporated herein.

In Fig. 1 Furthermore, the Luftahsaugschlitze 13 are still recognizable for the fan of the engine, which are located in the tool head 14 remote from the region just before the activation surfaces 28 of the switch.

In Fig. 2 the main components of the power tool 10 within the housing 12 can be seen. The electric tool 10 is according to the invention equipped with a self-supporting electric motor 16 which has a self-supporting stator 18, at the first, the tool head 14 facing the end of a first support member 20 is fixed, which preferably consists of plastic. On the opposite second side of the stator 18, a second support member 22 made of plastic is provided. Both support members 20, 22 are described below with reference to Fig. 4 described way screwed through the stator 18 therethrough. On the second support member 22 is also still a control electronics 23 added, which is indicated only schematically. The tool head 14 is received on the first support member 20. The housing 12, by which the power tool 10 is enclosed to the outside, is attached to both support members 20, 22. Overall, therefore, the motor 16 together with the support members 20, 22, the supporting structure to which all other components of the power tool 10 are attached.

By this design, a particularly space-saving and weight-saving construction can be achieved, which also allows a particularly favorable installation.

In Fig. 3 is the power tool 10 according to Fig. 2 shown enlarged, in about 90 ° relative to the position according to Fig. 2 twisted arrangement, but the housing is removed and essentially the engine is shown together with the two support parts.

Out Fig. 3 is the shape of the two support members 20, 22 easy to see, On the first support member 20 receiving surfaces 25 are provided for receiving optical switches on each side, as will be explained in more detail below.

In Fig. 3 Furthermore, a tool drive shaft accommodated in the tool head 14, together with a tool fastened thereto, is also schematically indicated by the dashed lines 17.

The stator 18 has a stator lamination stack 31, through which the first and the second support part 20, 22 are screwed by means of screws 43 to form a compact unit which is fixedly connected to the stator lamination stack 31.

The detailed structure of the power tool 10 is made Fig. 4 to see a longitudinal section through the power tool according to Fig. 3 shows. The motor 16 has an armature 32 which is mounted on a motor shaft 34. At the end of the motor shaft 34 facing away from the tool head 14, the latter is supported by means of a bearing 40, which is held in a bearing shell of the second support part 22. At the opposite end of the motor shaft 34 is mounted by means of a bearing 39 on the tool head 14. In the transition region between the first support member 20 and the tool head 14, a fan 38 can be seen on the motor shaft 34th is attached. The fan 38 are associated with 14 air outlet openings 42 in the tool head.

The intake of air is thus carried out by the electric motor 16 via intake ports 13 (FIG. Fig. 1 ) at the opposite end, while the air outlet of the cooling air takes place on the tool head 14, which is advantageous in order to keep the entry of foreign particles into the engine as low as possible. For naturally the strongest dust accumulation occurs in the area of the tool head 14. Between the armature 32 and the fan 38, the collector 36 of the electric motor 16 designed as a universal motor is provided. The associated brushes are still based on Fig. 5 explained in more detail.

Out Fig. 4 Furthermore, it is still possible to screw the two support parts 20, 22 through the stator lamination stack 31. The tool head 14 is screwed in a manner not shown with the first support member 20.

Fig. 5 shows an enlarged sectional view of the power tool 10 in the lateral longitudinal section in the region between the tool head 14 and armature 32nd

On the first support member 20 are each opposite to the top of the power tool 10 and 180 ° on the other hand offset on the bottom of a brush holder 54 is fixed, in which a brush (coal) 56 is added. For the pressure of the brush 56 each serves a brush spring 58, the in Fig. 5 is shown schematically. It is conceivable in that of insulating plastic. prepared first support member 20 to provide a contacting possibility for the brush 56 directly by an electrical connection 59 to the stator 18 and to the field windings 19 is created. Of course, this can also be done in a conventional manner by connecting cable.

From the perspective cross-sectional view according to Fig. 11 it can be seen that the housing 12 is oval in the area of the brushes 56. Since the diameter in one direction is predetermined by the brushes 56, a smaller diameter is achieved by the oval shape in the other direction perpendicular thereto. This results in an improved ergonomics when gripping the housing 12 at this point.

The first support member 20 is configured as an air guide, the inner surface ensures a targeted air flow of cooling air through the motor 16 to the blower 38 through, while a nozzle effect can be achieved.

In Fig. 5 Furthermore, a tensioning lever 30 accommodated on the tool head 14 can be seen, which serves for clamping and unclamping the tool 17. Since the power tool 10 is to be operated only with the clamping lever 30 closed, the tension lever 30 is associated with a sensor is checked by the continuous, whether the tensioning lever 30 is in its closed clamping position. For this purpose, a light-optical switch 52 is provided at the upper end of the tool head 14, which is actuated via a displaceable by the clamping lever 30 switching element 53. If the clamping lever 30 is closed, the switching element 53 is displaced, which leads to the release of a light beam, which is transmitted via optical fibers, which is evaluated by an associated evaluation logic.

Out Fig. 6 the structure of the optical switch used in the power tool 10 can be seen closer. Each optical switch has two optical fibers, one of which is designed as a transmission conductor, which is coupled to an LED, while the other optical fiber is designed as a receiving conductor and is connected to an associated evaluation unit. In the case shown, two associated optical fibers each terminate at a certain distance in the form of prisms, so that light can pass therebetween. If there is no object between these two ends, the light passes from the transmitting conductor into the receiving conductor, which is registered by the evaluation logic.

In Fig. 6 now a total of six light guides 63, 64, 66, 67, 71, 72 are shown, which are each received in recesses 62 of a shaped body 61. The molded body 61 is part of a support member 61 whose shape Fig. 7 is closer to see. The shaped body 61 is substantially a plate made of a suitable plastic which is suitably curved in the direction of extension of the optical fibers 63 to 72 received therein. The plastic material of the molded body 61 preferably has mechanical and optionally acoustically damping properties in order to dampen shocks better. Since the light guides 63-72 are placed in associated recesses in the form of grooves 62, they are particularly well protected against environmental influences from the outside, so that a reliable operation is ensured. In addition, a favorable signal / noise ratio is ensured as a result of the predetermined by the recesses 62 distances and fixes the light guide in its course. For this purpose, preferably rigid optical fibers are used, which are three-dimensionally curved in the desired shape.

In the illustrated case, each two ends of mutually associated light guides 63, 64 and 66, 67 and 71, 72 each associated with an elongated recess 65 and 68 or 70, which extend from the two ends in the region of the prisms to the outside extends. In this recess 65, 68, 70 can engage an associated switching element, through which the light passage between the two ends can be interrupted.

In Fig. 6 is the recess 68 between the two light guides 66, 67 associated with a slider 55 which is displaceable by means of the switching element 53 in the region between the two prism ends, so as to interrupt the passage of light. In the switch 73, to which the two light guides 71, 72 are assigned, a switching element 74 is provided in the region of the recess 70, which is pivotally received on the first support member 20 and with a switching tongue 76 in the region of the recess 70 between the two prism ends Light guide 71, 72 can get.

The support member 60 further includes a suitable recess to allow mounting of the brush holder 54 with brush 56 and brush spring 58. In Fig. 6 an associated fastening screw 79 can be seen.

Fig. 7 shows an overall view of the support member 60 together with optical fibers 63-72.

Out Fig. 8 It can be seen how the respective light guides 63-72 can be combined to form a prefabricated optical fiber bundle 84, which are preferably rigid and are held together by a common receptacle 86. In this recording wells for connecting LEDs for associated transmitter diodes are added and connections for receiver elements. In Fig. 8 only one LED 87 is indicated by way of example.

From the FIGS. 9 and 10 It can be seen how the support element 60 was placed with the light guides received therein on the top of the two support members 20, 22 and was inserted directly on the tool head 14. When subsequently mounted housing seals this preferably with the edges of the support member 60 from. The support member 60 thus lies in a directly adjacent to the patch housing position, wherein the optical fibers received therein are securely protected against any ingress of dirt or the like.

In Fig. 10 Furthermore, the slightly angled course of the support element 60 in the region of the receptacle 86 is still recognizable, on which the transmitter LEDs and receiver elements are arranged. Likewise are off Fig. 10 the switches 73 and 90 associated switching elements 74 and 91 can be seen, through which the light transmission between cooperating optical fibers can be interrupted. It is also conceivable, of course, a radiation from behind.

Claims (24)

1. An electrical tool comprising an electric motor (16) for driving a tool (17), comprising a motor shaft (34), a stator (18), an armature (32), a commutator (36) with brushes (56), and a fan (38), wherein the commutator (36) is arranged between the fan (38) and the winding core of the armature (32), wherein a first supporting part (20) and a second supporting part (22) are attached to both ends of the stator (18), and wherein the brushes (56) are surrounded by the first supporting part (20), characterized in that the first supporting part (20) is configured as an air guide ring which allows an air flow between the fan (38) and the opposite end of the electric motor (16) along the armature (32) and the brushes (56).
2. The electrical tool according to claim 1, characterized in that the stator (18) is configured as a self-supporting stator (18), in that the brushes (56) are attached to the first supporting part (20) by means of a brush holder (54), and in that the motor shaft (34) is mounted on both supporting parts (20, 22) or on parts attached thereto.
3. The electrical tool according to claim 1 or 2, characterized in that at least one switch (73, 90) is attached to the supporting parts (20, 22).
4. The electrical tool according to claim 1, 2 or 3, characterized in that control electronics (23) for controlling the electric motor (16) are held on one of the two supporting parts (22).
5. The electrical tool according to any of the proceeding claims, characterized in that the brushes (56) together with the brush holder (54) and at least one switch (73) are held on the first (20) of the supporting parts (20, 22), and in that the control electronics (23) and at least one switch (90) are held on the second (22) of the supporting parts (20, 22).
6. The electrical tool according to any of the proceeding claims, characterized in that the two supporting parts (20, 22) are connected to a housing (12).
7. The electrical tool according to any of the proceeding claims, characterized in that a tool head (14), into which the tool (17) can be inserted, is attached to the first supporting part (20).
8. The electrical tool according to claim 7, characterized in that the motor shaft (34) is mounted in bearings (39, 40) on the tool head (14) and on the second supporting part (22).
9. The electrical tool according to claim 8, characterized in that the tool head comprises a gearbox (21).
10. The electrical tool according to any of claims 6 to 9, characterized in that a switch (73, 90) is attached at least to the first supporting part (20) and can be operated via an activation surface (27, 28) which is held on the housing (12).
11. The electrical tool according to any of the proceeding claims, characterized in that mutually opposite brush holders (54) are held on the first supporting part (20).
12. The electrical tool according to any of the proceeding claims, characterized in that means (59) for electrical connection of the brushes (56) to the stator (18) are provided on the first supporting part (20).
13. The electrical tool according to claim 11 or 12, characterized in that a grip surface (24), which tapers in the area between the two mutually opposite brush holders (54), is provided on the first supporting part (20).
14. The electrical tool according to any of claims 11 to 13, characterized by a housing (12) which is oval in the area of the brushes (56).
15. The electrical tool according to any of the proceeding claims, characterized in that at least one activation surface (27, 28) for operation of a switching element (74, 91) or a switch (73, 90) is provided at least on one of the two supporting parts (20, 22).
16. The electrical tool according to any of the proceeding claims, characterized in that the supporting parts (20, 22) are produced from insulating material, preferably from a plastic.
17. The electrical tool according to any of the proceeding claims, characterized in that at least one switch (52, 73, 90) or a sensor are provided and have two optical fibers (63, 64, 66, 67, 71, 72), a transmitter and a receiver, as well as a monitoring element (53, 74, 91) for influencing the light signals which are transmitted between the optical fibers (63, 64, 66, 67, 71, 72).
18. The electrical tool according to 17, characterized in that a mounting element (60) is provided for holding the optical fibers (63, 64, 66, 67, 71, 72) and has a molding (61) in which two or more recesses (62) are provided, in which optical fibers (63, 64, 66, 67, 71, 72) can be inserted.
19. The electrical tool according to 18, characterized in that the molding (61) comprises holders (86) for transmitting or receiving elements (87) which are associated with the optical fibers (63, 64, 66, 67, 71, 72), or for switching elements for influencing radiation which is transmitted by the optical fibers (63, 64, 66, 67, 71, 72).
20. The electrical tool according to claim 18 or 19, characterized in that the molding (61) comprises holders (86) for holding LEDs (87).
21. The electrical tool according to claim 18, 19 or 20, characterized in that the molding (61) interacts with the housing (12) of the electrical tool (10) in order to seal the optical fibers (63, 64, 66, 67, 71, 72) which are held in the molding (61), and/or transmitting or receiving elements (87) or switching elements (74, 91), which are coupled to them, against contamination by dust or the like.
22. The electrical tool according to claim 21, characterized in that the molding (61) together with the housing (12) forms a completely sealed unit.
23. The electrical tool according to any of claims 18 to 22, characterized in that the molding (61) is composed of a vibration-damping and/or acoustically damping material.
24. The electrical tool according to any of the proceeding claims, characterized in by at least three manually operated switches (27, 28), which preferably allow operation from the front (on the right or left) or from the rear.

Images